1/3. Evidence for abnormally regulated alternative rna processing of mu chain gene in B-lymphoblastoid cells from Bloom's syndrome.Selective IgM deficiency is commonly found in patients with Bloom's syndrome. In this study, mu mRNA synthesis was investigated in B-lymphoblastoid cells transformed by Epstein-Barr virus (LCL) from a patient with Bloom's syndrome who showed selective IgM deficiency. LCL established from the patient with Bloom's syndrome well expressed IgM molecules in their surface, but scarcely produced secreted IgM, compared with healthy controls. The JH hybridization patterns of digested dna of LCL from the patient with Bloom's syndrome showed the rearrangement of VDJ as well as those of control LCLs. The mu mRNA was well detected, but mu s C-terminal mRNA was poorly detected compared with control LCLs, indicating that secreted mu mRNA was poorly transcribed though membrane-bound mu mRNA was well transcribed. These results suggest that alternative rna processing of mu chain gene is abnormally regulated in LCL from patients with Bloom's syndrome.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/3. Epstein-Barr virus in a malignant lymphoproliferative disorder of B-cells occurring after thymic epithelial transplantation for combined immunodeficiency.A fatal disseminated polyclonal malignant lymphoproliferative disorder of B-cells (immunoblastic sarcoma) developed shortly after a second thymic epithelial peritoneal implant in a 5-yr-old girl with combined immunodeficiency. The immunodeficiency was characterized by low T-cell numbers and function, very low levels of thymic hormone, dysgammaglobulinemia, and an inability to mount a primary antibody or cell-mediated response to new antigens. At necropsy, the thymus fulfilled morphological criteria for thymic dysplasia. Epstein-Barr virus (EBV) antigen and dna were identified in neoplastic infiltrates in the lymph nodes and thymus by immunofluorescence for the EBV nuclear antigen and by EBV-specific complementary rna/dna hybridization. No antibodies to nuclear antigen, early antigen, or viral capsid antigen of EBV were identified in the serum. The concurrence of these events suggests that the thymic epithelial implant itself may have been instrumental in the pathogenesis of this neoplasm. It is proposed that the thymus may have provided factors which indirectly potentiated the proliferation of EBV-infected B-cells, possibly by induction of nonspecific T-helper cells and perhaps through other thymic humoral factors. It is suggested that some forms of immunoblastic sarcoma, even when polyclonal, and especially those which arise in immunocompromised hosts, may, in some instances, represent an opportunistic form of EBV-induced B-cell neoplasia.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/3. Tubulo-interstitial nephritis associated with polyomavirus (BK type) infection.We studied viral injury to the kidney in a six-year-old boy with hyperimmunoglobulin M immunodeficiency who presented with irreversible acute renal failure and eventually died after five months of dialysis. Renal biopsy at the time of his presentation revealed a predominantly tubulo-interstitial process with numerous viral inclusions that were identified as polyomavirus. urine cultures showed a massive viruria with BK-type, polyomavirus. The kidney disease was end stage, with persistence of bk virus identified by morphologic techniques and by culture. dna hybridization analysis showed virus in low concentration in the lymph nodes, spleen, and lungs. The marked viruria, the high concentration of bk virus, and the extensive distribution of viral antigen throughout the kidney all suggest that infection with bk virus was the basis of the severe renal parenchymal injury.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |